After 2004's experience I decided to make a small boat (not another raft) in 2005 to watch Boston's 4th of July fireworks. At the time, my work had plenty of scrap acrylic around, and my boss let me use some to make a see-through boat. It took me about a day to design the hull, which has a dory cross-section (the sides splay out at 15 degrees), with a pointed bow (60 degrees) and a punt-like stern (30 degrees). I sized the boat so that I would be comfortable laying with my head against the stern, since I planned on getting a space near to the fireworks barges in the Charles River. It took about 24 hours to cut and glue the acrylic pieces: I should have been more patient, but I wanted to let all of the joints cure for a day, to make sure they were at full strength.

The plastic pieces were "glued" together with a solvent (methyl-ethyl ketone, or MEK), which chemically melts the parts together. The only tool I could find to cut the large parts I needed was a jigsaw. I wasn't patient enough with the jigsaw to make very straight cuts, and thus good cemented joints, so to help with waterproofing I ran some silicone sealant along all of the joints and let it cure overnight. I tested the water-tightness of the boat right before my group started off down the river. There were a few small leaks, so I did my best to seal them up quickly. In the end, the boat did have a few pinhole leaks that I couldn't plug, but I brought in a lot more water with my paddling than leaked in through the seams. I had to bail periodically after I got to my spot, but it was only every 20-30 minutes, and the leakage seemed to stay at a constant rate.

Acrylic has a density of 1.09 grams per cubic centimeter, so I did the math and figured out that 3L of air would be enough to keep the boat and anchor from sinking to the bottom if the boat capsized. So, I attached an empty 5 gallon water jug to the boat so I wouldn't loose all of that work if the worst happened. The jug also served as a nice place to put the glow sticks I used as a marker light after dark. The marker light is one of the items required to take a boat out on the river at night; the other items are a life jacket for every person, an anchor and a paddle.

Overall, I'm quite pleased with how the boat turned out. I was really surprised how well it portaged and how it handled in the water, considering I didn't have much knowledge of naval architecture other than a few hours reading on the internet. Since there was no seat or other division in the boat, and the bottom of the hull was flat, I had to work at centering myself and the cargo on the floor of the boat so that the everything was stable when I paddled. In hindsight, had I not taken so many extra things I didn't end up using, I would have had a few extra centimeters of freeboard, and I wouldn't have had to worry so much about keeping balanced and evening out the waterline. I had to speak with the state police this year, too, but all they made me do was tie up with another, larger boat before the fireworks started, which I was planning on doing anyway. I ended up leaving the boat behind in my dorm when I graduated.